This is a strange type of routine where you do 100 total reps of one exercise. It’s not the same as 10×10 or GVT however. Take your 10 rep max and use 40-50% of that. Rest between sets is 10-30s. I just recomend you use it for bodybuilding purposes ie if your arms aren’t growing you do 100 reps of biceps and triceps. However for the deranged I supposed heres a routine to try.
Dumbbell Bench 100 Reps
Lateral Raises 100 Reps
Curls 100 Reps
Skullcrushers 100 Reps
Leg Press (or Squat prepare to vomit lol) 100 Reps
Hamstring Curls 100 Reps
I recommend this only as a challenge or supplement to your usual workouts.